This invention relates in general to adjustable frame apparatus, and in particular to an adjustable frame for providing storm window or screen protection to an existing window or similar opening.
The use of auxiliary windows, such as storm windows, to fit over existing windows is well known, especially in household applications. If properly designed and fitted, storm windows provide a substantially airtight seal around the existing window and sash, and thereby reduce the amount of heat loss or heat gain that otherwise may occur through the existing window sash. This reduction in heat transfer takes place because the storm window effectively seals air leaks that are present between the fixed and moving parts of an existing window frame, and because the volume of air enclosed between the existing window and the storm window defines a dead air space which itself provides a insulating function.
Storm windows of the prior art have generally been custom manufactured for window frames of various standard sizes, and sometimes include slidable screen panels as well as window panes for storm window use. Such custom storm windows are relatively expensive to manufacture, and generally cannot be modified or tailored by the installer to fit windows of nonstandard configuration or dimension. The capital cost of equiping an entire home with custom storm windows of the prior art may be prohibitive and difficult to justify in many applications, moreover, even though savings in energy costs to heat or air-condition the home can be anticipated once the storm windows are in place. There is, accordingly, a need for a relatively inexpensive storm window that provides the energy-saving and comfort benefits of existing storm window structure, without the attendant expense of the conventional custom storm window.
Prior art attempts have been made to provide relatively inexpensive storm window structure which could be purchased by the individual home owner and installed as a do-it-yourself project, thereby eliminating the installation cost as well as a portion of the purchase cost associated with custom storm windows. These prior art structures have been less than satisfactory, however, for a number of reasons. Since the windows found in a typical house usually have a variety of overall frame dimensions, it becomes necessary for the retailer either to stock storm windows of many different sizes, or to carry storm window frame sections that the homeowner can cut as necessary to fit his particular windows. The cut-and-fit storm window structure of the prior art have been less than satisfactory, however, because many homeowners lack the skills and/or the tools necessary to provide a "custom-fit" or factory-built appearance to their cut-and-fit efforts. The lack of a custom appearance is especially evident at the corners of the typical rectangular storm window, where the absence of an accurate 45.degree. miter joint greatly detracts from the overall appearance of an installed storm window.